1. Field of the Invention
The present invention relates to a fuel injection valve used in an internal combustion engine, and more particularly to a fuel injection valve that opens and closes a fuel path by an electromagnetically driven movable member thereof.
2. Description of the Related Art
A conventional type of fuel injection valve is disclosed in Japanese Unexamined Patent Publication No. H11 (1999)-22585, which describes a technique for improving valve behavior responsivity through reduction of fluid resistance in movement of an anchor by providing a vertical groove on the periphery of the anchor.
In Japanese Unexamined Patent Publications No. S58 (1983)-1778863 and No. H18 (2006)-22721, there is disclosed a movable member comprising a cylindrical anchor part, a plunger part located at the center part of the anchor part, and a valve disc mounted at the top end of the plunger part, wherein a magnetic attraction gap is provided between an end face of the anchor part and an end face of a stationary core having a fuel introduction bore for introducing fuel centerward, and wherein an electromagnetic coil is provided for applying a magnetic flux to a magnetic path including the magnetic attraction gap. A technique for forming an axially extending through hole in the anchor part is also described in the patent publications noted above.
Japanese Unexamined Patent Publication No. H14 (2002)-528672 discloses a structure in which a plunger is disposed through the center of an anchor part, and an axially extending through hole that penetrates the anchor part is provided in the periphery portion of the anchor part.